The hemispheric view of Venus, as revealed by more
than a decade of radar investigations culminating in the 1990-1994
Magellan mission, is centered at 270 degrees east longitude. The Magellan
spacecraft imaged more than 98% of Venus at a resolution of about 100
meters; the effective resolution of this image is about 3 km. A mosaic of
the Magellan images (most with illumination from the west) forms the image
base. Gaps in the Magellan coverage were filled with images from the
Earth-based Arecibo radar in a region centered roughly on 0 degree
latitude and longitude, and with a neutral tone elsewhere (primarily near
the south pole). The composite image was processed to improve contrast and
to emphasize small features, and was color-coded to represent elevation.
Gaps in the elevation data from the Magellan radar altimeter were filled
with altimetry from the Venera spacecraft and the U.S. Pioneer Venus
missions. An orthographic projection was used, simulating a distant view
of one hemisphere of the planet.